Cross-site Scripting (XSS) Affecting jupyterlab package, versions *


Severity

Recommended
0.0
critical
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
0.35% (28th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ECHOLATEST-JUPYTERLAB-18507867
  • published2 Aug 2026
  • disclosed13 May 2026

Introduced: 13 May 2026

CVE-2026-42557  (opens in a new tab)
CWE-79  (opens in a new tab)

How to fix?

There is no fixed version for Echo:latest jupyterlab.

NVD Description

Note: Versions mentioned in the description apply only to the upstream jupyterlab package and not the jupyterlab package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5.7, JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by the user. This vulnerability is fixed in 4.5.7.

CVSS Base Scores

version 3.1